Processing apparatuses for semiconductor wafers (hereinafter, simply referred to as “wafers”) perform processing to conduct rear face grinding with a protective adhesive sheet stuck to a circuit surface of the wafers and to perform singulation into a plurality of chips while sticking a dicing tape. In adhesive sheets for use in such processing, ultraviolet curable (photoreactive) adhesives are adopted as adhesives. After the processing as described above, adhesives are cured by an ultraviolet ray irradiating apparatus to weaken the adhesion thereof so that peeling off is easily performed so as to prevent the wafers from being damaged.
Such an ultraviolet ray irradiating apparatus is disclosed in Patent document 1, as an example. In the ultraviolet ray irradiating apparatus in this document, such an arrangement is adopted that a lamp house is provided so as to enable head-swinging motion thereof with respect to a wafer stuck with an ultraviolet curable adhesive tape, and the head-swinging speed thereof is controlled responding to the irradiation angle of an ultraviolet ray so that a small space is realized and integrated light quantity of the ultraviolet ray is maintained constant in a whole region to be irradiated.    [Patent document 1] Japanese Patent Application Laid-Open No. 2001-290000